The present invention relates to a continuous wire feed arrangement for stapling apparatus. Such wire feed arrangements are used in many applications, for instance in assembly lines for stapling booklets or in connection with rotating offset printing machines.
The German Pat. No. 756,731 discloses a device in which the stapling wire is alternately withdrawn from two reels in the form of a V fed to a common channel or nozzle. Thereby the wire is contacted by means of a feeler and at the end of the wire transport a gear unit is actuated. The gear unit, when actuated, imparts opposite movements to the transporting rolls of the exhausted reel and the replacement reel, whereby wire from the replacement reel is transmitted to the channel and the residual wire of the exhausted reel is withdrawn from the channel. A problem with this construction is the proper return movement of the residual wire and the proper introduction of the leading end of the next wire into the channel. In addition, the switching over from one to the other reel requires a relatively long time, which leads, especially at fast operating machines, to a great number of unstapled products, which have to be discarded.
A continuous wire feed mechanism for stapling apparatus is further known from the DD-PS No. 100,437. In this wire feed mechanism the stapling wire is also alternately in form of a V fed to a guide channel. The wire transport is produced by means of tiltably mounted rolls, which after exhaustion of the wire from the first reel move the wire from the second reel over a downstream arranged pair of transporting rolls to the common guide channel. The disadvantage of this construction is also a relatively large time period which expires during the changeover from the first to the second wire reel, and vice versa, and the resulting production of unstapled products.